Structural hypotheses that link the relative advantage in certain ethnic enclaves to the structure of their economies are tested in a comparative analysis of the Cuban and black businesses in Miami. Findings suggest that the more advantaged community, the Cuban enclave, is characterized by highly interdependent industries, ones which are less dependent on majority industry; the less advantaged community, the black enclave, is characterized by weakly interdependent industries, ones which are more dependent on majority industry. In addition, hypotheses are suggested which link the structuring of enclave economies to traditional concerns with background cultural, historical, and situational influences. The usefulness of input-output analysis and the limitations of secondary data are discussed.